So, I'm just curious: what are the hot trends lately in show bettas? Superblack, marble/fancy, butterfly? What seems to be the most desired/sought after color/pattern in the show world? The most uncommon?

There's really no trends at shows. The fish will either fit a color standard or it will not.
Color is very dificult and you have to be very selective. Butterflies have to be 50/50, Solids must me clean, multis need 3+ colors, etc.
The IBC handbook, which you can only get if you're a member, will explain all of this.

Thanks guys.
vilmarisv: what I meant was, what is popular with breeders. What are people breeding, and what colors seem to have a "wow" factor? What isn't seen much at shows? I'm getting an IBC membership as an early Christmas present, so I can finally read The Almighty Handbook!